27 January 2015

The roots of the formation of Airbus Industrie are tied more to the abilities of one man more than any other individual in the early history of the Airbus consortium- Roger Béteille. A graduate of the prestigious École Polytechnique, he was the technical director of Sud-Aviation in the mid-1960s. Sud-Aviation produced the Caravelle and it was Béteille who was the director of the jet's flight test program. In postwar Europe prior to the formation of Airbus, the Caravelle was only one of two commercial aircraft programs to make money (the other being the BAC One-Eleven). He also worked closely with Hawker Siddeley on the Concorde program- this was an experience that unique among the French technocrats of the time, gave him a close working relationship and mutual respect of the British aerospace establishment. In the aerospace industry of France in those days, someone of Béteille's skills was unique given his flawless English, the respect afforded by the British engineering staff at Hawker, and his political skills in working with several European nations in the course of his career at Sud-Aviation.

In the summer of 1966 there were three proposed commercial aviation projects that were commanding the attention of the European industry. The first one was the BAC Two-Eleven, a successor to the successful BAC One-Eleven. That summer BAC was riding high on the success of the One-Eleven which at the time was one of Britain's most successful and profitable aerospace programs. But it was already facing significant competition from the Douglas DC-9 and the Boeing 737 and BAC had been lobbying the British government for support to launch the Two-Eleven which would have been powered by a new engine Rolls-Royce was developing, the RB.211, that would also go to the Lockheed Tristar. The Two-Eleven was a larger development of the One-Eleven that for the most part, was intended to get British European Airways (BEA) to drop its interest in the Boeing 727-200. The problem with BAC was that it was heavily committed to the Concorde program and had little financial resources to devote to the further developing the Two-Eleven which is why they were keen on approximately $100 million in launch funding from the British government.

Hawker-Breguet-Nord HBN 100

In the previous year (1965), the head of Breguet Aviation, Henri Ziegler (who later became Airbus's first president) had inked an agreement with fellow French firm Nord Aviation and Hawker Siddeley in the UK to jointly work on a widebody twin called the HBN 100 that was largely the product of Hawker's engineers at their Hatfield facility. The HBN 100 was to have two variants, one with a passenger capacity for 225 and a stretched one with a capacity for 260. The planned engines were to be either the Pratt & Whitney JT9D that was under development at the time for the Boeing 747 or the Rolls Royce RB.178 which was a three-shaft demonstrator engine called the "Super Conway" that eventually led to the RB.211. At the same time as the HBN 100, Sud-Aviation (Roger Béteille's firm) was working the Galion which was very similar in layout, appearance and size to the HBN 100. The Sud-Aviation Galion evolved from what had started out as an enlarged Caravelle.

Sud Aviation Galion

In 1966 Béteille invited his friends from Hawker Siddeley to Sud Aviation's facility in Toulouse to see if the design work on the HBN 100 and the Galion might be aligned towards a common joint project. That invitation for Arthur Howes, who headed the Hawker team, to come to Toulouse is what gave birth to the Airbus. It soon become a joint program with engineers from all the involved companies shuttling down to Toulouse as needed as the designs of the Galion and the HBN 100 were more closely aligned. That December at a meeting in London, France, Great Britain, and West Germany- I'll soon get to how the Germans entered the picture- decided that a single consortium would build a widebody twin. At time time, Concorde had two production lines- one in France and one in the UK, and on top of the financial costs of the program, the duplication of effort was something Roger Béteille wished to avoid so that an attractively priced aircraft could be offered to the world's airlines. It was agreed that in exchange for Rolls Royce developing a new engine for their design, the Sud Aviation Galion would form the baseline design to work from with the HBN 100 being sidelined.

It was obvious at the time that any joint effort would be spearheaded by Britain and France, the only Western European nations at the time that had the industrial capacity for large commercial aircraft design and production. But the West Germans were keeping an eye on the developments and the use of the name "Airbus" in reference to the nascent project actually came from them. Even though it was twenty years after the end of World War II, the German aircraft industry was still in shambles. Many legendary names like Messerschmitt and Dornier were still around, but even those entities were hollow shells of their former selves. What engineering staff hadn't left Germany after the war debated the future of their industry and decided the future lay in collaboration on a civil aircraft project. The year before Roger Béteille invited the British to meet in Toulouse, seven German aircraft companies (ATG Siebelwerke, Bolkow, Dornier, Flugzeug-union Sud, Hamburger Flugzeugbau, Messerschimitt and VFW) formed Studiengruppe Airbus (the Airbus Study Group) to determine what sort of aircraft the future airline market would need. It was this grouping of German companies that contributed the Airbus name to the young enterprise. It was at the following year's Farnborough Air Show that German participation was formalized. Up to that point, the Germans had been working on their own but it was decided that what the French and British had come up with baselined off the Sud Aviation Galion was a suitable candidate for their contribution to the effort. Officially becoming Airbus, each nation decided that one company from each nation would take the lead for that nation's contribution. Hawker Siddeley would lead the British contribution, Sud Aviation would lead the French contribution and the German Airbus Study Group was reorganized into a formal consortium of their own, Airbus AG, to lead the German contribution.

But what to name this aircraft? Arthur Howes of Hawker Siddeley was partial to the name "Obelix" which was the giant in the Asterix series of comic books popular in those days. It was apparent, though, that the name had to be something that was essentially neutral to British, French and German interests. One evening at a dinner in Sud Aviation's Paris headquarters the upper level of management at Sud Aviation asked why a name for the aircraft hadn't been found yet. Different ideas were punted about before Howes himself spoke up as a joke and said "I propose we call it the HSA 300" and the room laughed as "HSA" was the initials of Hawker Siddeley Aviation. But Howes continued "H- Hawker Siddeley, S- Sud Aviation, A- Airbus, and 300 because it's a nice round number." As everyone enjoyed Howes' joke, it suddenly donned on him- why don't we call it the A300? 300 is still a nice round number closest to the proposed design's seating capacity and if "A" was used, the aircraft would always appear before Boeing in any alphabetical listing. Howes idea proved popular and the nascent enterprise's new design would be marketed as the Airbus A300.

22 January 2015

On 21 June 2004, Mike Melvill piloted SpaceShipOne past the edge of space, becoming the first commercial astronaut in aviation history. Melville and his wife, Sally, were Burt Rutan's very first employees when they moved out to California in 1974 to join Rutan in his business. But Melvill is nothing like the 433 individuals that preceded him into space. I think Dave Hirschman's article for the June 2013 issue of AOPA Magazine "The Unlikeliest Astronaut" put it best in the following paragraph:

Unlikeliest astronaut. Mike Melvill doesn't fit the typical military-trained, academically overachieving astronaut profile. The South African native failed a math course and never finished high school. He raced motorcycles and became a machinist at 17. He married his childhood sweetheart, Sally, and they emigrated to the United States in the late 1960s. He became a U.S. citizen in 1972, and his motivation to fly was a dislike of airline travel—not a dream of exploration.

To understand how Mike Melvill's unlikely career in aviation is inextricably linked with that of Burt Rutan, we have to step back a bit and take a look at Burt Rutan's first aircraft design, a homebuilt piston pusher he called the VariViggen. Rutan began the design work on the VariViggen in 1963 while he was still an undergraduate at California Polytechnic State University. He would graduate in 1965 third in his class with a degree in aeronautical engineering and soon landed work at Edwards AFB as a civilian flight engineer. Living in Lancaster at the time he was working at Edwards, Rutan began construction of the VariViggen in his garage in 1968 after five years of doing his own model experiments with subscale models and wind tunnel testing that basically was Rutan mounting design iterations of the VariViggen to a test rig he built that could be clamped to the luggage rack of his station wagon. Using his day job experience as a flight test engineer, he was able to use these tests to refine the VariViggen's configuration before starting assembly. Around the time he was ready to start taxi testing the VariViggen, he left California in 1972 and took a job with Jim Bede's aircraft company in Newton, Kansas, as the director of development for the BD-5 homebuilt aircraft. In his spare time, he prepared the VariViggen for its taxi and flight tests with the help of some of Bede's engineers and employees. He made the VariViggen's first flight in April that year and embarked on a nine-week flight test program before flying the aircraft to the 1972 Oshkosh Air Show, demonstrating the aircraft to the experimental homebuilt aircraft community and selling the blueprints for pilots to build their own VariViggen. He returned to California in 1974 and formed the Rutan Aircraft Company.

The Rutan VariViggen

It was there at Oskhosh in 1972 that Mike Melvill met Burt Rutan and purchased a set of blue prints for the VariViggen. Melvill was a machinist with a gift for tinkering working for a tool and die company in Indiana that specialized in industrial box cutting machines. Traveling all over to customers, Melvill figured if he learned to fly, traveling for business would be much more enjoyable than just a series of tedious waits in airport terminals across the country. He began working on his own Nesmith Cougar aircraft (a high wing homebuilt design from the 1950s) which was 2/3 finished before he sold it off and picked up another Cougar which was 90% completed. That second Cougar was the one Melvill was flying for four years before he met Rutan at Oshkosh.

Melville liked the VariViggen design as it accommodated two people and three suitcases easily. With his wife's support, they bought a new house in Indiana that had the room for Mike to build his own VariViggen. Melvill can tell you exactly how much time it took him to finish his VariViggen- "Three years, one month, twenty-two days". He had followed Rutan's blueprints exactly until he got to the landing gear retraction mechanisms. Melvill didn't like the design and with a tool and machinist background, redesigned the system to his liking, fabricating his own parts at work. Melvill's VariViggen was the first one built aside from Rutan's and that made Rutan a regular visitor to see the construction progress. One day, when Rutan was visiting, he found out Melvill's wife was a bookkeeper (and a pilot in her own right as well) and that she worked at the same company as her husband. Rutan offered both of them the opportunity to come to California and work for him. The story goes that Rutan was more in need of his wife's accounting skills than Melvill's piloting and machinist skills:

"I need her worse than I need you!"

Melvill and his wife are one of the ten original owners of Rutan's company, Scaled Composites and his first employees as well. Melvill still has his VariViggen with 4,200 hours on the airframe. He would go on to become Rutan's main test pilot and the general manager of his company with his wife as the head of human resources. Being Rutan's main test pilot, Melvill was the pragmatist counterpart to Rutan's dreams and often Rutan talked with Melvill several times a day about his ideas. Most of the time Melvill would be first person to know what new ideas Rutan was contemplating. From the same AOPA article:

“He came into my office almost every morning,” Melvill said. “He would say something like, ‘I think we’ve developed the technical expertise to build a twin, or a jet.’ But I’ll never forget the day he said he thought we had the technical expertise to fly an aircraft into space. It was something I’d never considered. We were doing a credible job with airplanes that flew about 200 miles an hour—but to get to space, we’d have to fly at Mach 3. It seemed too ambitious to seriously contemplate, and I was intimidated.”

17 January 2015

As design work by various aerospace companies began on the Space Shuttle program in the late 1960s, it was a given that the Orbiter would have its own jet engines. Having its own air breathing engines offered three advantages- they would allow atmospheric flight testing much like any other aircraft was tested and pilots could practice landings in the run up to an orbital mission. The engines also facilitated ferry flights, repositioning the Orbiter amongst various facilities (landing, launch, overhaul, etc.). Having its own jet engine propulsion also gave the Orbiter cross range capability upon return from orbit. Some designers envisioned the Orbiter rendezvousing with a tanker for additional jet fuel. But in the ascent and in orbit, jet engines and fuel for those engines was dead weight that subtracted from potential payload. Even if designers went with an Orbiter design that was unpowered on its landing, the 1970 and 1971 design studies prominently featured a fully reusable two stage Space Shuttle with a big flyback booster that would have to have its own jet engines. Some of the designs for the flyback booster were massive with a need for as many as twelve jet engines. Soon the design of the flyback booster itself began to take on technical challenges that rivaled that of the Orbiter design itself. The weight of up to twelve jet engines and the necessary jet fuel cut into the payload of liquid hydrogen and liquid oxygen for the booster's rocket engines. Many of the flyback booster designs would need approximately 150,000 lbs of jet fuel (for comparison, a Boeing 777-200ER has a fuel capacity of roughly 300,000 lbs). Consideration was then given to using liquid hydrogen as fuel for the jet engines which would cut out the need for jet fuel tanks. In June 1970, NASA issued contracts to GE to study the feasibility of using liquid hydrogen in the F101 engine being developed for the B-1 bomber. Pratt and Whitney also got a similar contract to study the use of liquid hydrogen fuel in the F401 engine, the planned naval derivative of the USAF's F100 engine planned for the F-15 Eagle. Both companies showed that liquid hydrogen fueled jet engines saved about 2500 lbs of weight per jet engine compared to conventionally-fueled jet engines. The weight savings was modest at best.

A typical high-key to low-key unpowered approach to landing

At the same time these studies were going on on how to save weight with Orbiter and flyback booster-mounted jet engines, with NASA there was a group at the Flight Research Center at Edwards AFB where unpowered landings were routine for many high speed research aircraft going back to the X-1 (the X-15 program being the most recent one at the time) and the graduates of the co-located Aerospace Research Pilot School had as a requirement that students demonstrate proficiency in unpowered landings using the school's Lockheed F-104 Starfighters which were throttled down to idle for the practice sessions. Even more demanding were the unpowered landings made by the lifting body program aircraft that lacked wings and derived their lift from their tubby fuselage designs. Regardless of what sort of aircraft was used, USAF test pilots and the NASA-FRC pilots used what was called "energy management" where they traded altitude for airspeed on the descent and used turns to bleed off speed in preparation for final approach. The first step in unpowered landings was the arrival at the "high key" which was high above the touchdown point. From the high key, a gradual 180 degree turn was made that allowed speed reduction and descent to the "low key" which was usually abeam the touchdown point. From the low key, the turn continued allowing more speed to bleed off and the descent to continue until lined up for final approach. If at any point the speed was excessive, speed brakes or gentle S-turns could be used to get down to the necessary airspeed. The lifting body pilots found that on final approach, diving at the runway touchdown point 15 degrees or more improved their accuracy as the speed improved the stability and the speedbrakes could be used to moderate the speed build up on final approach. An assessment by one of the experienced lifting body pilots in September 1970 showed that in 30 landings on a 10,000 foot runway from altitudes as high as 90,000 feet and speeds as high as Mach 2, the dispersion of the landing points was only 250 feet.

However, the astronaut office in Houston at the Manned Spaceflight Center headed by Deke Slayton felt that unpowered landings for the Orbiter were too risky. Slayton was concerned that the test pilots were more proficient at unpowered landings than his astronauts would be, especially if they were returning from a 7-10 day orbital mission. The astronauts' views carried considerable weight for good reason and it took the USAF to swing the design work in favor of unpowered landings.

I had posted previously that the Space Shuttle program's development phase was taking place during a period of budget austerity. One of the keys to navigating the budgetary climate of the day was to be sure to secure as much political support as possible since Congress determined the program budget. But in 1970 the program had some close calls, narrowly avoiding funding cuts in both the House and Senate. The Air Force offered to lend its support as it saw opportunity in the Shuttle program to launch heavy reconnaissance satellites. But NASA had baselined the Orbiter design at the time with a 25,000 lb payload to orbit. The USAF wanted to put its heavy reconnaissance satellites into polar orbit and the Orbiter needed a payload capacity of 40,000 lbs. That much payload weight into polar orbit (and unable to take advantage of the Earth's rotation for additional boost) was equal to a 65,000 lb payload launched for the Kennedy Space Center. NASA informed the USAF that the payload had to be baselined at 25,000 lbs due to the weight of the jet engines and their fuel. But it was apparent from the Congressional battles that NASA needed a strong ally like the USAF, so the jet engines were dropped from the Orbiter design and that allowed the payload capacity to orbit to meet the USAF requirements.

The idea of onboard jet engines didn't end, though. NASA shifted towards the idea of removable kit that could be used for flight testing, ferry flights, and for return from orbit if the payload wasn't maxed out. This also coincided with the 1971-1972 time frame when the flyback booster was dropped as too much of a technical risk and the Space Shuttle began to look more like its final design- an Orbiter with an external tank and solid rocket boosters in what was called the TAOS configuration- Thrust Assisted Orbiter Shuttle. The significant weight savings by going to a TAOS configuration also helped cut development risk as there was a considerable amount of experience already with solid rocket boosters and large external tank structures to hold cryogenic fuels.

The test pilots at NASA-FRC persisted in their opinion that jet engines were completely unnecessary in the Orbiter design. They had their long experience of over 10,000 unpowered landings since the X-1 program as their proof, but the astronauts insisted that the Orbiter was a much bigger aircraft than many of the X-planes. Another round of tests then were held by NASA-FRC, this time using their B-52 Stratofortress carrier aircraft. Set up in a high drag configuration with the engines at idle, pilots successfully and accurately landed the B-52. NASA-FRC then got some lifting body pilots who had never flown anything as big as the B-52 and had them fly the bomber through a simulated unpowered landing using energy management. They were able to land successfully and when the same pilots were asked to land the B-52 using a conventional powered low angle approach, none of them were able to do so. The test pilots the FRC even brought into two United Airlines pilots to fly the B-52 in simulated unpowered landings and they had no issue doing so, reporting that such landings were much easier than conventional landings. The test pilots then followed up the B-52 tests with the same tests using NASA's Convair 990 which could simulate the Orbiter aerodynamics on landing.

The final iteration of a jet-engine powered Shuttle Orbiter (from the Dennis Jenkins book)

NASA finally got agreement to go to exclusively unpowered landings on return from orbit for the Shuttle Orbiter, but the jet engines still didn't go away. At the time of Rockwell's award in 1972, the Orbiter design featured two engines that deployed from the payload bay and two more engines that could be mounted on struts. Less than six months later, the Orbiter design dropped the internally mounted jet engines completely and they were to be mounted as a kit on the flat underside when needed for flight testing and ferry missions. It finally took the ferry range to kill the engines completely from the Orbiter design. The Orbiter was similar in size to a Douglas DC-9 but had twice the weight. It had a lot of drag since it wasn't optimized for atmospheric flight and the delta wing was highly loaded. With five jet engines mounted in pods on the underside and tank of jet fuel in the payload bay, the Orbiter had a ferry range of only 500 miles. With Space Shuttle sites across the nation and contingency fields overseas, a 500 mile range was simply unacceptable. NASA looked at aerial refueling during ferry, but this added complexity to a design that was already experiencing cost overruns. In February 1974, NASA deleted the jet engine requirement completely. As a result, both for flight testing and ferry flights, the Orbiter would need a carrier aircraft, but fortunately that was a lot more straightforward a development process!

The Buran analog with its four AL-31 jet engine nacelles

Interestingly in the Russian Buran Shuttle program, there was an aerodynamic test analog designed OK-GLI that made 25 atmospheric test flights with four Lyulka/Saturn AL-31 jet engines mounted in nacelles in the aft fuselage. A fuel tank sat in the payload bay. The AL-31 is the jet engine that is used on the Sukhoi Su-27 Flanker. Nine taxi tests and 25 test flights were made using the Buran analog from December 1984 to December 1989. The engines were used to takeoff and then were throttled back on the descent to landing. All of the flight testing took place at the Baikonur Cosmodrome. The operational Buran, however, would not have jet engines at all and the Antonov An-225 Myria was developed as the carrier aircraft to ferry the Buran orbiter.

Source:Development of the Space Shuttle 1972-1981: History of the Space Shuttle, Volume Two by T.A. Heppenheimer. Smithsonian Institution Press, 2002, pp85-92. Space Shuttle: The History of the National Space Transportation System- The First 100 Missions by Dennis Jenkins. Specialty Press, 2008, pp187-192. Photos: NASA, Wikipedia, Dennis Jenkins.

12 January 2015

Here's another face virtually unknown to aviation history but very important- this is Marine Corps Major General Keith B. McCutcheon, the architect of modern close air support as we know it. During World War II, most air strikes against targets on the battlefield were called "direct air support" or DAS against preplanned targets with no guidance from the boots on the ground. Even the air strikes in support of the island hopping campaign in the Pacific were DAS-type missions.

In 1942 the Marine Corps began experimenting with ALPs- Air Liason Parties, who were specially trained Marines who used radios and smoke markers to direct pilots to targets. In 1943, they made their combat debut on the island of Bougainville during the Solomon Islands campaign. But their use was limited and faced strong operational opposition from the Army. In fact, the Army's operational manual at the time recommended against close air support for fear of friendly fire casualties.

Army resistance to CAS doctrine eased in 1944, when Lieutenant Colonel Keith McCutcheon formalized the training of the Marine Corps ALPs. He pulled together all that had been written about the use of the ALPs in at Bougainville and developed a formal curriculum and training plan. Any Marine aviator that was performing CAS missions had to prove their abilities through intensive training under McCutcheon's close eye. At the time, the Marines were working with the Army's 1st Cavalry Division clearing Luzon of Japanese forces. His commanding officer, Colonel Clayton Jerome, asked him to come up with a way of using close air support to cover the 1st Cavalry Division's left flank. His operational experience at that point was flying combat missions in the Dauntless dive bomber in support of Marines during the liberation of the Philippines. Despite what appeared to be limited experience, McCutcheon had a keen sense of the needs of the infantryman, he considered the pilots in his charge Marines first and aviators second. In a short period of time, McCutcheon and his staff wrote five training manuals and eleven supplements for pilots on close air support doctrine and the training even applied to ground personnel attached to the ALPs. McCutcheon wanted everyone from the pilot in the cockpit to the radioman on the ground to thoroughly understand each other's jobs and abilities before going to combat. Over 500 men from Marine Air Group 24 and the Army's 37th Division were trained in just two months in the midst of the Philippine campaign from October to December 1944. The improved ALPs went into operational use for the first time during Marine Corps action on the main Philippine island of Luzon in February 1945.

McCutcheon himself as head of Marine Air Group 24 flew combat missions in the Douglas SBD Dauntless who had their targets called in by ALPs in radio-equipped Jeeps moving with ground units. As a result, during the battles on Luzon, McCutcheon's SBD pilots quickly gained a reputation for lethal accuracy in the battlefield.

McCutcheon's methods were further refined during the Korean War with not just ALPs but also airborne ALPs we know know as FACs- Forward Air Controllers. In Korea, the FACs were usually North American T-6 Texans. By the time of the arrival of Marine Corps A-4 Skyhawk and F-4 Phantom units in Vietnam in the spring and summer of 1965, the squadrons were organized into Marine Air Groups (MAGs)- a Marine Air Group was made up usually of one type of aircraft and was tasked to fight at least 90 days in support of a Marine brigade. Several MAGs formed a Marine Air Wing (MAW). And in Vietnam in 1965, MAW-1 was headquartered at Da Nang AB and led by none other than Keith McCutcheon himself.

As the commanding general of Marine Air Wing 1, McCutcheon protected his air assets with zeal to keep them from being subordinated to the USAF and US Navy. Despite numerous "official" moves to strip the Marine Corps of their autonomy, in practice, 70% of Marine CAS missions in Vietnam were in support of Marines and controlled by Marines.

In 1970 McCutcheon was to get his fourth star as but was unable to assume his final post as Assistant Commandant of the Marine Corps due to ill health. In recognition of his distinguished career and what he did for Marine aviation, Congress passed special legislation to have McCutcheon listed as a retired full four star general anyway. He got his fourth star on 1 July 1971 and passed away from cancer less than two weeks later. He was laid to rest at Arlington National Cemetery.

07 January 2015

Some of the carriers of TF38 at their anchorage on the eve of Phase One

Contrary to common belief, the dropping of the atomic bombs on Hiroshima and Nagasaki didn't make the invasion of Japan unnecessary. In fact, the invasion of Japan began on 1 July 1945 when Task Force 38 left its anchorage in the Philippines to begin Phase One of Operation Olympic, the invasion of the southernmost of the Home Islands, Kyushu. The amphibious landings on Kyushu were set for November 1945 and Kyushu would then be used as a base of operations for Operation Coronet, the invasion of Honshu and the capture of Tokyo set for the spring of 1946. By this point in the war, the US Navy's Fast Carrier Task Forces had eclipsed the Imperial Japanese Navy's Kido Butai (Mobile Strike Force) of the first half of the Pacific War as the most powerful naval strike unit of the war. Phase One of Operation Olympic was for the powerful Task Force 38 to conduct raids on the Japanese Home Islands in preparation for the November landings. Commanding TF38 would be Admiral William "Bull" Halsey and Vice Admiral John S. McCain. TF38 was made up of Task Groups, each group centered around 5-6 aircraft carriers supported by 2-3 battleships, cruisers and 2-3 destroyer squadrons. Halsey flew his flag aboard the battleship USS Missouri while McCain had his flag on the newest Essex-class fleet carrier, the USS Shangri-La. (the prior link will take you to a detailed order of battle for TF38). In concert with the US Army Air Forces' B-29 Superfortress offensive, TF38's aircraft would be hitting pinpoint targets that the B-29s were unsuited to go after- airfields, harbors and dockyards, coastal shipping and transportation chokepoints.

Once within striking range of the Home Islands on 10 July, the sailors and airmen of the TF38 awaited the kamikaze onslaught and expected fierce air resistance over the target areas. To their surprise, they literally had air superiority over even Tokyo with little effort. The Japanese were expecting the landings in October and saw no use in fighting the growing number of American aircraft attacking the Home Islands, instead they chose to stockpile and husband their airpower for use to defend against the expected landings. The aviators of TF38 turned their attention to coastal targets around Kyushu, but the pickings were slim. With intelligence reports indicating a far better target would be the coal industry on the northern Home Island of Hokkaido, TF38 moved north to disrupt Japanese industry by going after its power source. The factories on Honshu, the main island, got over 80% of their coal from Hokkaido in the north. Disrupting the rail lines on Hokkaido would further hamper the transport of coal from the mines southward. On 14 July alone 850 sorties were carried out against various targets in Hokkaido from airfields, rail lines and harbors. Many of the harbors were crowded with merchant ships who were trying to avoid the minefields that had been sown by the B-29 Superfortresses.

Turning into the wind off the coast of Japan, July 1945

It was during the strikes on Hokkaido that the Navy discovered the Achilles heel of the Japanese industry. As there were no bridges or tunnels linking Hokkaido to Honshu at the time, they relied on train ferries to move coal cars from the port of Hakodate on Hokkaido across the Tsuguru Strait to the port of Aomori on Honshu. In the 1920s as Japan's industrialization increased, four 3,400 ton ferries were built that could carry 25 rail cars across the Tsuguru Strait. Larger ferries were built in the late 1920s that could carry up to 43 rail cars. A dozen of these ships were the only way to move coal from the mines in Hokkaido to the factories in Honshu. Eight of the ferries were sunk by TF38's aviators and an eighth was forced aground. The air wing of the USS Essex alone accounted for four of the precious train ferries. Coal shipments were quickly moved by the Japanese to smaller coastal merchantmen, but they were inadequate for the task and they were just as much targets for the prowling aircraft of TF38 as the train ferries. The effect was dramatic- in just two days, the amount of coal available to factories on Honshu dropped by a staggering 80%.

The contribution by targeting the train ferries presented the Navy's brass with a dilemma. For most of the Pacific War and the years prior carrier aviation strategy centered around attacking and sinking the enemy fleet at sea, but the carrier strikes against the coal industry of Hokkaido showed that hitting unglamorous targets like train ferries contributed for more to the war effort. This would have a great influence on one of the task group commanders of TF38, Rear Admiral Arthur Radford. In the postwar period, Radford served as the Vice Chief of Naval Operations, Commander of the Pacific Fleet and Chairman of the Joint Chiefs of Staff. In those various capacities he consistently pushed for a strong naval aviation arm.

Source:Whirlwind: The Air War Against Japan 1942-1945 by Barrett Tillman. Simon & Schuster, 2010, pp 199-202. Photos: US Navy

02 January 2015

The Williams FJ44 engine of the CitationJet family has a fascinating history as it's based on the F107 turbofan used on American cruise missiles like the ALCM and the Tomahawk. Williams International started out with marine turboshafts and APUs before getting into small turbofan engines. Sam Williams and his namesake company would rise to prominence in the aviation industry with miniature turbofans but his real dream was a civilian turbofan for general aviation. In the 1980s Williams envisioned a new class of turbofans based on the F107 design that would allow for a new class of general aviation aircraft that were jets half the cost and size of current bizjets with the field performance and economy of turboprop twins.

Sam Williams believed so much in his FJ44 engine design that development continued through the 1980s in the absence of any launch order or production application. Keep in mind that this class of engine had never been used in general aviation and Williams International had never made a civilian production jet engine. Through the 1980s, Williams lobbied numerous general aviation manufacturers about his concept for a light jet aircraft and how he had a superbly economical engine to make such an aircraft feasible. The first manufacturer to agree was Rutan's Scaled Composites who flew the Triumph in 1988. Rutan's design never entered production but it did mark the FJ44's first flight. The next manufacturer to agree to use twin FJ44s was Swearingen in its SJ30 design- even though the aircraft flew, Swearingen and the SJ30 have passed through many ownership changes serial production has yet to occur. Williams' big break came with the third manufacturer- Cessna was looking for an efficient and higher performing successor to its iconic Citation line and launched the Cessna 525 CitationJet family in 1992 with a very substantial order of Williams FJ44 engines, vindicating Sam Williams' dream.

Sam Williams

The FJ44 is a joint venture between Williams International and Rolls-Royce and was the company's first civilian engine and first manned aircraft engine. Simplicity and reliability were key to this new class of aircraft and as such, the FJ44 engine has only 700 parts total, 1/4 that of many other bizjet powerplants. The Cessna CitationJet series was the first production application for the FJ44 engine. It wasn't enough to have a simple engine, it also had to have performance and basing the FJ44 on the F107 cruise missile engine gave the FJ44 that foundation. In fact, the F107 that the FJ44 is derived from was such an impressive accomplishment that it won the Collier Trophy- it has 1/10th the weight of the Pratt & Whitney JT8D engine but has the same specific fuel consumption and thrust-to-weight ratio. That performance pedigree translated over well into the FJ44 and it made the engine successful. On the Cessna CitationJet series, the economy and performance of the new engine made the new jet a leap in performance over the Citation 500 series it replaced. While aerodynamic improvements are part of the equation, the FJ44 engine's performance and economics are a large contributor. Compared to a Citation 500 at an identical mid-cruise weight, the CitationJet goes 13% farther with 17% less fuel and it does this 40% faster than the original Citation with the FJ44s having a lower thrust output than the JT15Ds used on the first Citations.

There are four engines in the FJ44 family. The lowest powered one was the first one, the FJ44-1 and it powers the Cessna CJ1 and CJ1+ of the CitationJet family and is also used on the Cessna Citation M2 as well as the Swedish jet trainer Saab Sk60. It has a thrust rating of 1900 to 2100 lbs. The FJ44-1 series first flew in 1988 and went into production in 1992.

The second engine in the family is the FJ44-2 and is based on the core and LP turbine of the FJ44 paired up with a larger fan and new compressor section for increased thrust. Its applications include the Cessna CJ2, the Beech/Raytheon Premier I, and the latest incarnation of the SJ30 design, Syberjet SJ30. Two of Rutan's designs fly with the FJ44, the Scaled Composites Proteus and the Virgin Atlantic Global Flyer that Steve Fossett flew around the world in solo nonstop in 2005. It's also used on two re-engining programs for the Citation 500 and the Learjet 25. The FJ44-2 has a thrust rating of 2300-2400 lbs thrust and went into production in 1997.

The next engine in the family is the FJ44-3 which has a new fan and compressor section for an increase in thrust rating to 3000 lbs. It powers the Cessna CJ2+ and CJ3+ and is used in Nextant's re-engining and remanufacture program of the Beech 400 as well as on a re-engining program for later Citation 500 variants. It went into production in 2004.

The top end member of the FJ44 family is the FJ44-4 with an increase in thrust to 3600 lbs with a larger fan and enlarged compressor. It also features a dual-channel FADEC for more efficiency. It powers the Cessna CJ4 along with the Beech 400XPR remanufacture/upgrade program for the Beech 400. The engine will also power the upcoming Pilatus PC-24 jet.

There is also a scale down of the FJ44 engine, the FJ33, which went into production in 2004 and has a thrust rating of 1000 to 1900 lbs. The fan is only 19 inches in diameter and it powers the Diamond D-Jet and the Cirrus Vision.

Unlike other manufacturers of small jet engines, the FJ44 has no turboprop derivative and there are no turboprops in the Williams portfolio. This is a reflection of Sam Williams' philosophy that given time and technological progress, light turbofans like the FJ44 will displace turboprop engines for most civilian aircraft applications. The FJ44 is one of the landmark engines of aviation history and Sam Williams has earned honors for creating an engine that gave rise to a whole new class of general aviation aircraft.

Source: The History of North American Small Gas Turbine Engines by Richard A. Leyes and William A. Fleming. American Institute of Aeronautics and Astronautics/Smithsonian Institution Press, 1999, pp383-429. Williams International http://www.williams-int.com/. Photos: Williams International

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